While schizotypal features are common during adolescence, they can also signal increased risk for the onset of schizophreniform disorders. Most studies with adolescents find that hallucination and delusion-like symptoms (positive schizotypal features) best predict future psychopathology. Still, the developmental process of positive schizotypy remains elusive, specifically with regards to 1) its relationships to negative and disorganization schizotypal dimensions; 2) its associations to maladaptive functioning during adolescence. This longitudinal study aimed to further characterize these relationships, thereby delineating "early and broadly defined psychosis risk mental states" (Keshavan et al., 2011). The current study presents the 3-year course of schizotypal trait expression in 34 clinical adolescents aged 12 to 18 years consulting for non-psychotic difficulties. Schizotypal expression was assessed twice using the Schizotypal Personality Questionnaire, accompanied by an examination of internalizing/externalizing problems using the Achenbach scales. Cross-sectional and longitudinal analyses were conducted to assess the expression and course of schizotypal dimensions; mediation analyses were further employed to highlight the developmental interactions promoting the maintenance of positive schizotypal expression. The results reveal that positive schizotypy, and more specifically unusual perceptual experiences, significantly declined during the study interval. Disorganization features were found to mediate the relationships between the negative and positive dimensions of schizotypy within and across evaluations. Somatic complaints and attentional difficulties further strengthened the expression of positive schizotypy during the study interval. These results suggest that the relationship between disorganization features and positive schizotypy may play a central role in establishing risk for psychosis during adolescence.

The expression of early delusion and hallucination-like symptoms, known as positive schizotypy (PS), holds predictive power for later development of psychotic disorders. However, little is known about the psychological and emotional processes promoting the expression of PS during adolescent development. Our study's objective was to examine the nature of the relationships between adolescent PS and two dimensions previously identified to contribute to adult positive symptoms of psychosis, metacognitive beliefs and anxiety. Using a structural equation modeling design, data from self-report questionnaires measuring anxiety, metacognitive beliefs, and PS were collected from 179 adolescents aged 12 to 19 years. Our results indicate that although metacognitive beliefs significantly influence adolescent PS and anxiety, maladaptive contradictory metacognitive beliefs specifically potentiate positive schizotypal expression in hallucination-prone adolescents. Furthermore, we observe that PS and anxiety entertain reciprocal relationships. These findings suggest that relationships between metacognitive beliefs, anxiety, and PS can already be observed during adolescence.

The present study points to modest performances of the MDQ-A and CBQ to detect BDs in adolescents, with diagnostic criteria for BD being unmet for a majority of patients who screened positive.